Nanoelectronics and Energy

We are an interdisciplinary research group that studies nanoelectronic devices made from colloidal semiconductor quantum dots (QDs). Colloidal QDs are nanometer-sized single crystals of semiconductor suspended in a solution that offer exciting opportunities for scientists and engineers to develop ultracheap, pervasive devices for emerging ubiquitous electronics and ambient intelligence era. Our research effort is concentrated in two fronts:

Photodetectors operating in the atmospheric transmission window of 8-12 μm (long wavelength infrared) are of great importance for civilian and military applications. These detectors do not require external source of illumination for day/night imaging, have high tolerance to airborne obscurants (such as fog, smoke, and dust), and are particularly effective in sensing human bodies. Current technology based on HgCdTe suffer from high cost of fabrication (>$50,000) and require cryogenic cooling system to achieve high detectivity which significantly increases the detector’s size, weight, and power consumption. These two factors have been persistent problems limiting their broad-scale applicability. Our thrust in this project is to develop new infrared sensing QDs that will offer significantly reduced fabrication cost (<$10) and to implement novel device structures for high sensitivity/high temperature infrared photo detection.

(2) Ambient energy harvesting using thermoelectric QDs

Breakthroughs in energy harvesting hold promise for “deploy-and-forget” wireless sensor networks and other distributed or portable power applications. In this regard, efficient energy harvesting from ubiquitous temperature gradients by means of silent, maintenance-free thermoelectric generators has been a long-standing goal. This project focuses on fabricating paper-based thermoelectric generators by merging naturally abundant cellulose papers with thermoelectric QDs. Leveraged by paper’s high flexibility and inherently low thermal conductivity, these low-cost paper devices have the potential to efficiently utilize heat available in natural and man-made environments by maximizing the thermal contact to heat sources that often have arbitrary geometries (e.g. pipes and human bodies).